%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Sajad Saeedi
% University of New Brunswick
% Copy Right 2012
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% ref: 
% S. Saeedi, L. Paull, M. Trentini, M. Seto, and H. Li, 
% Map Merging Using Hough Peak Matching, 
% Proceedings of the IEEE/RSJ International Conference on 
% Intelligent Robots and Systems (IROS), 
% Vilamoura, Portugal, October 7-12, pp. 4683 - 4688.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% in this function just occuoied cells are extracted to be used by Radon
% transform
% 将占据的格子提取出来
function map = get_just_occ(in_map)
[m n] = size(in_map);
map = zeros(m, n);
for r = 1:m
  for c = 1:n
    if in_map(r,c) < 0
       map(r,c) = -1;
%      map(r,c) = in_map(r,c);
    end
  end
end

end